Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A056210
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A056210 Primes p for which the period of reciprocal = (p-1)/5. +0
7
11, 251, 1061, 1451, 1901, 1931, 2381, 3181, 3491, 3851, 4621, 4861, 5261, 6101, 6491, 6581, 6781, 7331, 8101, 9941, 10331, 10771, 11251, 11261, 11411, 12301, 14051, 14221, 14411, 15091, 15131, 16061, 16141, 16301, 16651, 16811, 16901 (list; graph; listen)
OFFSET

1,1

COMMENT

Cyclic numbers of the fifth degree (or fifth order): the reciprocals of these numbers belong to one of five different cycles. Each cycle has the (number minus 1)/5 digits.

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

Index entries for sequences related to decimal expansion of 1/n

MATHEMATICA

f[n_Integer] := Block[{ds = Divisors[n - 1]}, (n - 1)/Take[ ds, Position[ PowerMod[ 10, ds, n], 1] [[1, 1]]] [[ -1]]]; Select[ Prime[ Range[4, 2000]], f[ # ] == 5 &]

CROSSREFS

Cf. A001913, A097443, A055628, A056157, A056211-A056217, A098680

Sequence in context: A041223 A041220 A098672 this_sequence A089298 A012154 A009055

Adjacent sequences: A056207 A056208 A056209 this_sequence A056211 A056212 A056213

KEYWORD

nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 02 2000

EXTENSIONS

Entry revised by N. J. A. Sloane (njas(AT)research.att.com), Apr 30 2007

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


AT&T Labs Research